DEMO LINK : http://demo.opencartclub.org/index.php?route=information/information&information_id=21

Fancy Before After Compare Image extension is a nice opencart extension, where you can show the before and after effects by defining two images. Best used by doctors, architects, designers, etc. to show the before and after effects on the same area of the web page. Highly configurable and backed with a 24x7 Customer Support package. This module is cross browser compatible and works on all the modern browsers. Bug Free and works great! Compatible with Opencart 2.0.1.0, 2.0.1.1, 2.0.2.0, 2.0.3.1, 2.1.0.1, 2.1.0.2 and 3.0.2.0. The Downloads Access and Extension Support is valid for 6 months from the date of purchase.